When Aldergrove tried to sue Lingus for a crazy amount of money a few months ago was it not stated in court that the reason they left to go to Harbour was because the base was unprofitable, it was either move to Harbour or withdraw totally from the NI market?
Is it not also the case that their summer program has grown since they moved to Harbour? Why would they continue to increase flights that there is allegedly no demand for? From my limited knowledge the holiday flights are all doing very well, I would be very surprised if they were suddenly stopped completely from next summer.
As Skipness says
BMI moved to BHD because their passengers wanted it, the airline serves the market not the other way round. Remember they even served BFS again when BA left and dropped it soon after.